Subject: [PATCH v4 08/26] mm: drop CONFIG_HAVE_ARCH_NODEDATA_EXTENSION

From: Mike Rapoport <[email-masked]>
Date: Wed, 7 Aug 2024 09:40:52 +0300

From: "Mike Rapoport (Microsoft)" <[email-masked]>

There are no users of HAVE_ARCH_NODEDATA_EXTENSION left, so
arch_alloc_nodedata() and arch_refresh_nodedata() are not needed
anymore.

Replace the call to arch_alloc_nodedata() in free_area_init() with a
new helper alloc_offline_node_data(), remove arch_refresh_nodedata()
and cleanup include/linux/memory_hotplug.h from the associated
ifdefery.

Signed-off-by: Mike Rapoport (Microsoft) <[email-masked]>
Tested-by: Zi Yan <[email-masked]> # for x86_64 and arm64
Acked-by: Dan Williams <[email-masked]>
---
 include/linux/memory_hotplug.h | 48 ----------------------------------
 include/linux/numa.h           |  4 +++
 mm/mm_init.c                   | 10 ++-----
 mm/numa.c                      | 12 +++++++++
 4 files changed, 18 insertions(+), 56 deletions(-)

diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index ebe876930e78..b27ddce5d324 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -16,54 +16,6 @@ struct resource;
 struct vmem_altmap;
 struct dev_pagemap;
 
-#ifdef CONFIG_HAVE_ARCH_NODEDATA_EXTENSION
-/*
- * For supporting node-hotadd, we have to allocate a new pgdat.
- *
- * If an arch has generic style NODE_DATA(),
- * node_data[nid] = kzalloc() works well. But it depends on the architecture.
- *
- * In general, generic_alloc_nodedata() is used.
- *
- */
-extern pg_data_t *arch_alloc_nodedata(int nid);
-extern void arch_refresh_nodedata(int nid, pg_data_t *pgdat);
-
-#else /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
-
-#define arch_alloc_nodedata(nid)	generic_alloc_nodedata(nid)
-
-#ifdef CONFIG_NUMA
-/*
- * XXX: node aware allocation can't work well to get new node's memory at this time.
- *	Because, pgdat for the new node is not allocated/initialized yet itself.
- *	To use new node's memory, more consideration will be necessary.
- */
-#define generic_alloc_nodedata(nid)				\
-({								\
-	memblock_alloc(sizeof(*pgdat), SMP_CACHE_BYTES);	\
-})
-
-extern pg_data_t *node_data[];
-static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
-{
-	node_data[nid] = pgdat;
-}
-
-#else /* !CONFIG_NUMA */
-
-/* never called */
-static inline pg_data_t *generic_alloc_nodedata(int nid)
-{
-	BUG();
-	return NULL;
-}
-static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
-{
-}
-#endif /* CONFIG_NUMA */
-#endif /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
-
 #ifdef CONFIG_MEMORY_HOTPLUG
 struct page *pfn_to_online_page(unsigned long pfn);
 
diff --git a/include/linux/numa.h b/include/linux/numa.h
index e5841d4057ab..b41b1569781b 100644
--- a/include/linux/numa.h
+++ b/include/linux/numa.h
@@ -33,6 +33,8 @@ static inline bool numa_valid_node(int nid)
 extern struct pglist_data *node_data[];
 #define NODE_DATA(nid)	(node_data[nid])
 
+void __init alloc_offline_node_data(int nid);
+
 /* Generic implementation available */
 int numa_nearest_node(int node, unsigned int state);
 
@@ -60,6 +62,8 @@ static inline int phys_to_target_node(u64 start)
 {
 	return 0;
 }
+
+static inline void alloc_offline_node_data(int nid) {}
 #endif
 
 #define numa_map_to_online_node(node) numa_nearest_node(node, N_ONLINE)
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 75c3bd42799b..2785be04e7bb 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -1836,14 +1836,8 @@ void __init free_area_init(unsigned long *max_zone_pfn)
 	for_each_node(nid) {
 		pg_data_t *pgdat;
 
-		if (!node_online(nid)) {
-			/* Allocator not initialized yet */
-			pgdat = arch_alloc_nodedata(nid);
-			if (!pgdat)
-				panic("Cannot allocate %zuB for node %d.\n",
-				       sizeof(*pgdat), nid);
-			arch_refresh_nodedata(nid, pgdat);
-		}
+		if (!node_online(nid))
+			alloc_offline_node_data(nid);
 
 		pgdat = NODE_DATA(nid);
 		free_area_init_node(nid);
diff --git a/mm/numa.c b/mm/numa.c
index 8c157d41c026..64e1b7d2c1ee 100644
--- a/mm/numa.c
+++ b/mm/numa.c
@@ -6,6 +6,18 @@
 struct pglist_data *node_data[MAX_NUMNODES];
 EXPORT_SYMBOL(node_data);
 
+void __init alloc_offline_node_data(int nid)
+{
+	pg_data_t *pgdat;
+
+	pgdat = memblock_alloc(sizeof(*pgdat), SMP_CACHE_BYTES);
+	if (!pgdat)
+		panic("Cannot allocate %zuB for node %d.\n",
+		      sizeof(*pgdat), nid);
+
+	node_data[nid] = pgdat;
+}
+
 /* Stub functions: */
 
 #ifndef memory_add_physaddr_to_nid
-- 
2.43.0